Glycerol and spent lye clarification - Illinois Institute of Technology

The titration method is open to the
objection that by precipitation by lead acetate
the impurities may not be perfectly removed,
anything left being oxidized and counted as
glycerol.
With the removal of all higher fatty acids
and all resins and carbonates, as well as
albuminoids, sulphides, thiocyanates, and
aldehydes, (which is accomplished by the
addition of basic lead acetate) the error due
to oxidation is eliminated with the elimina*-
tion of all carbon. The lower fatty acids
such as acetic, butyric, caprylic, and formic
(should they escape the metallic salts in the
lye clarification) are not attacked by chromic
acid. The chlorides and aldehydic compounds
are removed alike with soluble silver salts in
either method.
Check determinations with the absorption
method agree very well with all percentages
of glycerol, wherae with the other methods at
hand results with low percentages are anything
but concordant